The present invention relates to implantable devices. More particularly, it relates to a valve prosthesis for cardiac implantation or for implantation in other body ducts.
There are several known prosthetic valves that have been previously described. U.S. Pat. No. 5,411,552 (Andersen et al.), entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY AND CATHETER FOR IMPLANTING SUCH VALVE PROSTHESIS, discloses a valve prosthesis comprising a stent made from an expandable cylinder-shaped thread structure comprising several spaced apices. The elastically collapsible valve is mounted on the stent with the commissural points of the valve secured to the projecting apices, which prevents the valve from turning inside out. Deployment of the valve can be achieved by using an inflatable balloon which in its deflated state is used to carry about it the valve structure to its position and, when inflated, deploys the stent in position to its final size. See, also, U.S. Pat. No. 6,168,614 (Andersen et al.) entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY and U.S. Pat. No. 5,840,081 (Andersen et al.), entitled SYSTEM AND METHOD FOR IMPLANTING CARDIAC VALVES.
In PCT/EP97/07337 (Letac, Cribier et al.), published as WO 98/29057, entitled VALVE PROSTHESIS FOR IMPLANTATION IN BODY CHANNELS, there is disclosed a valve prosthesis comprising a collapsible valve structure and an expandable frame on which the valve structure is mounted. The valve structure is composed of a valvular tissue compatible with the human body and blood, the valvular tissue being sufficiently supple and resistant to allow the valve structure to be deformed from a closed state to an opened state. The valvular tissue forms a continuous surface and is provided with guiding means formed or incorporated within, the guiding means creating stiffened zones which induce the valve structure to follow a patterned movement in its expansion to its opened state and in its turning back to its closed state. The valve structure can be extended to an internal cover which is fastened to the lower part of the valve structure to prevent regurgitation.
There are several known methods currently used for replacing aortic valves and several types of artificial prosthetic devices. Mechanical valves are commonly used in several different designs (single and double flap) manufactured by well-known companies such as St. Jude, Medtronic, Sulzer, and others. Some of the main disadvantages of these devices are: a need for permanent treatment of anticoagulants, noisy operation, and a need for a large-scale operation to implant.
There is a wide range of biologically based valves made of natural valves or composed of biological materials such as pericardial tissue. These too are made and marketed by well-known companies such as Edwards Lifesciences, Medtronic, Sulzer, Sorin, and others.
Polymer valves are new and are not yet in use, but several companies are in the process of developing such products. A new type of prosthesis is being considered, based on artificial polymer materials such as polyurethane.
The present invention introduces several novel structural designs for implantable valves. An aspect of the present invention deals with the possibility of implanting the valve percutaneously, i.e., inserting the valve assembly on a delivery device similar to a catheter, then implanting the valve at the desired location via a large blood vessel such as the femoral artery, in a procedure similar to other known interventional cardiovascular procedures. The percutaneous deployment procedure and device has an impact on the product design in several parameters, some of which are explained hereinafter.
The percutaneous implantation of medical devices and particularly prosthetic valves is a preferred surgical procedure for it involves making a very small perforation in the patient""s skin (usually in the groin or armpit area) under local anesthetic and sedation, as opposed to a large chest surgery incision, which requires general anesthesia, opening a large portion of the chest, and cardiopulmonary bypass. This percutaneous procedure is therefore considered safer.
The present invention provides a series of new concepts in the field of aortic valves and other human valves.
It is therefore thus provided, in accordance with a preferred embodiment of the present invention, a valve prosthesis device suitable for implantation in body ducts, the device comprising:
a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, the support stent provided with a plurality of longitudinally rigid support beams of fixed length; and
a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet,
whereby when flow is allowed to pass through the valve prosthesis device from the inlet to the outlet the valve assembly is kept in an open position, whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow.
Furthermore, in accordance with another preferred embodiment of the present invention, the support stent comprises an annular frame.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly has a tricuspid configuration.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is made from biocompatible material.
Furthermore, in accordance with another preferred embodiment of the present invention, the valve assembly is made from pericardial tissue, or other biological tissue.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is made from biocompatible polymers.
Furthermore, in accordance with another preferred embodiment of the present invention, the valve assembly is made from materials selected from the group consisting of polyurethane and polyethylene terephthalate (PET).
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly comprises a main body made from PET (polyethylene terephthalate) and leaflets made from polyurethane.
Furthermore, in accordance with another preferred embodiment of the present invention, said support stent is made from nickel titanium.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams are substantially equidistant and substantially parallel so as to provide anchorage for the valve assembly.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams are provided with bores so as to allow stitching or tying of the valve assembly to the beams.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams are chemically adhered to the support stent.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is riveted to the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is stitched to the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, said beams are manufactured by injection using a mold, or by machining.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is rolled over the support stent at the inlet.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve device is manufactured using forging or dipping techniques.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly leaflets are longer than needed to exactly close the outlet, thus when they are in the collapsed state substantial portions of the leaflets fall on each other creating better sealing.
Furthermore, in accordance with another preferred embodiment of the present invention, said valve assembly is made from coils of a polymer, coated by a coating layer of same polymer.
Furthermore, in accordance with another preferred embodiment of the present invention, said polymer is polyurethane.
Furthermore, in accordance with another preferred embodiment of the present invention, the support stent is provided with heavy metal markers so as to enable tracking and determining the valve device position and orientation.
Furthermore, in accordance with another preferred embodiment of the present invention, the heavy metal markers are selected from gold, platinum, iridium, or tantalum.
Furthermore, in accordance with another preferred embodiment of the present invention, the valve assembly leaflets are provided with radio-opaque material at the outlet, so as to help tracking the valve device operation in vivo.
Furthermore, in accordance with another preferred embodiment of the present invention, said radio-opaque material comprises gold thread.
Furthermore, in accordance with another preferred embodiment of the present invention, the diameter of said support stent, when fully deployed is in the range of from about 19 to about 25 mm.
Furthermore, in accordance with another preferred embodiment of the present invention, the diameter of said support stent may be expanded from about 4 to about 25 mm.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams are provided with bores and wherein the valve assembly is attached to the support beams by means of U-shaped rigid members that are fastened to the valve assembly and that are provided with extruding portions that fit into matching bores on the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams comprise rigid support beams in the form of frame construction, and the valve assembly pliant material is inserted through a gap in the frame and a fastening rod is inserted through a pocket formed between the pliant material and the frame and holds the valve in position.
Furthermore, in accordance with another preferred embodiment of the present invention, the main body of the valve assembly is made from coiled wire coated with coating material.
Furthermore, in accordance with another preferred embodiment of the present invention, the coiled wire and the coating material is made from polyurethane.
Furthermore, in accordance with another preferred embodiment of the present invention, a strengthening wire is interlaced in the valve assembly at the outlet of the conduit so as to define a fault line about which the collapsible slack portion of the valve assembly may flap.
Furthermore, in accordance with another preferred embodiment of the present invention, the strengthening wire is made from nickel titanium alloy.
Furthermore, in accordance with another preferred embodiment of the present invention, there is provided a valve prosthesis device suitable for implantation in body ducts, the device comprising a main conduit body having an inlet and an outlet and pliant leaflets attached at the outlet so that when a flow passes through the conduit from the inlet to the outlet the leaflets are in an open position allowing the flow to exit the outlet, and when the flow is reversed the leaflets collapse so as to block the outlet, wherein the main body is made from PET and collapsible leaflets are made form polyurethane.
Furthermore, in accordance with another preferred embodiment of the present invention, support beams made from polyurethane are provided on the main body and wherein the leaflets are attached to the main body at the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, said support beams are chemically adhered to the main body.
Furthermore, in accordance with another preferred embodiment of the present invention, there is provided a valve prosthesis device suitable for implantation in body ducts, the device comprising:
a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, the support stent provided with a plurality of longitudinally rigid support beams of fixed length;
a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet; and
substantially equidistant rigid support beams interlaced or attached to the slack portion of the valve assembly material, arranged longitudinally.
Furthermore, in accordance with another preferred embodiment of the present invention, there is provided a crimping device for crimping the valve device described above or in claim 1, the crimping device comprising a plurality of adjustable plates that resemble a typical SLR (Single Lens Reflex) camera variable restrictor, each provided with a blade, that are equally dispersed in a radial symmetry but each plate moves along a line passing off an opening in the center, all plates equidistant from that center opening.
Furthermore, in accordance with another preferred embodiment of the present invention, the multiple plates are adapted to move simultaneously by means of a lever and transmission.
Furthermore, in accordance with another preferred embodiment of the present invention, there is provided a method for deploying an implantable prosthetic valve device from the retrograde approach (approaching the aortic valve from the descending aorta) or from the antegrade approach (approaching the aortic valve from the left ventricle after performing a trans-septal puncture) at the natural aortic valve position at the entrance to the left ventricle of a myocardium of a patient, the method comprising the steps of:
(a) providing a balloon catheter having a proximal end and a distal end, having a first and second independently inflatable portions, the first inflatable portion located at the distal end of the catheter and the second inflatable portion adjacently behind the first inflatable portion;
(b) providing a guiding tool for guiding the balloon catheter in the vasculature of the patient;
(c) providing a deployable implantable valve prosthesis device adapted to be mounted on the second inflatable portion of the balloon catheter;
(d) for the retrograde approach, guiding the balloon catheter through the patient""s aorta using the guiding tool, the valve device mounted over the second inflatable portion of the balloon catheter until the first inflatable portion of the balloon catheter is inserted into the left ventricle, whereas the second inflatable portion of the balloon catheter is positioned at the natural aortic valve position;
(e) for the antegrade approach, guiding the balloon catheter through the patient""s greater veins, right atrium, left atrium, and left ventricle using the guiding tool, the valve device mounted over the second inflatable portion of the balloon catheter until the first inflatable portion of the balloon catheter is inserted into the left ventricle, whereas the second inflatable portion of the balloon catheter is positioned at the natural aortic valve position;
(f) inflating the first inflatable portion of the balloon catheter so as to substantially block blood flow through the natural aortic valve and anchor the distal end of the balloon catheter in position;
(g) inflating the second inflatable portion of the balloon catheter so as to deploy the implantable prosthetic valve device in position at the natural aortic valve position;
(h) deflating the first and second inflatable portions of the balloon catheter; and
(i) retracting the balloon catheter and removing it from the patient""s body.
Furthermore, in accordance with another preferred embodiment of the present invention, the guiding tool comprises a guide wire.
Furthermore, in accordance with another preferred embodiment of the present invention, there is provided a method for deploying an implantable prosthetic valve device at the natural aortic valve position at the entrance to the left ventricle of a myocardium of a patient, the method comprising the steps of:
(a) providing a balloon catheter having a proximal end and a distal end, having a first and second independently inflatable portions, the first inflatable portion located at the distal end of the catheter and the second inflatable portion adjacently behind the first inflatable portion;
(b) providing a guiding tool for guiding the balloon catheter in the vasculature of the patient;
(c) providing a deployable implantable valve prosthesis device adapted to be mounted on the first inflatable portion of the balloon catheter, and a deployable annular stent device adapted to be mounted over the second inflatable portion of the balloon catheter, the deployable implantable valve prosthesis device and the deployable annular stent kept at a predetermined distant apart;
(d) guiding the balloon catheter through the patient""s aorta using the guiding tool, the valve device mounted over the first inflatable portion of the balloon catheter and the deployable annular stent mounted over the second inflatable portion of the balloon catheter, until the first inflatable portion of the balloon catheter is positioned at the natural aortic valve position;
(e) inflating the second inflatable portion of the balloon catheter so that the deployable stent device is deployed within the aorta thus anchoring the deployable annular stent and the coupled valve device in position;
(f) inflating the first inflatable portion of the balloon catheter so as to deploy the implantable prosthetic valve device in position at the natural aortic valve position;
(g) deflating the first and second inflatable portions of the balloon catheter; and
(h) retracting the balloon catheter and removing it from the patient""s body.
Furthermore, in accordance with another preferred embodiment of the present invention, a valve prosthesis device suitable for implantation in body ducts comprises:
an expandable support frame, the support frame provided with a plurality of longitudinally rigid support beams of fixed length; and
valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet,
whereby when flow is allowed to pass through the valve prosthesis device from the inlet to the outlet the valve assembly is kept in an open position, whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow.
Furthermore, in accordance with another preferred embodiment of the present invention, the support frame comprises a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams have a U-shaped cross section.
Furthermore, in accordance with another preferred embodiment of the present invention, a holder is used to secure the plaint material to the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, the support frame comprises three segments that form a circular assembly when assembled.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams point inwardly with respect to a central longitudinal axis of the device.
Furthermore, in accordance with another preferred embodiment of the present invention, the device is further provided with a restricting tapered housing, for housing it in a crimped state.
Furthermore, in accordance with another preferred embodiment of the present invention, hooks are provided to secure the device in position after it is deployed.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams comprise longitudinal bars having a narrow slit used as the commissural attachment so that extensions the pliant material are tightly inserted through it.
Furthermore, in accordance with another preferred embodiment of the present invention, the extensions of the pliant material are wrapped about rigid bars serving as anchorage means.
Furthermore, in accordance with another preferred embodiment of the present invention, extensions of the pliant material are sutured to each other at the rigid bars.
Furthermore, in accordance with another preferred embodiment of the present invention, a bottom portion of the pliant material is attached to the inlet.
Furthermore, in accordance with another preferred embodiment of the present invention, the support beams are each provided with a rounded pole, forming a loop through which the pliant material is inserted.
Furthermore, in accordance with another preferred embodiment of the present invention, the pliant material is provided with longitudinal bars attached to the pliant material at positions assigned for attachment to the support frame, in order to prevent localized stress from forming.
Furthermore, in accordance with another preferred embodiment of the present invention, the device is further provided with longitudinal bars having protrusions that are inserted in bores in the pliant material, a sheet of PET and through bores provided on the support beams.
Furthermore, in accordance with another preferred embodiment of the present invention, pliant material is sutured leaving the slack portions free of sutures.
Furthermore, in accordance with another preferred embodiment of the present invention, a connecting member with a split portion is used to connect leaflets of the pliant material to the support beams, the split connecting member compressing the pliant material in position.
Furthermore, in accordance with another preferred embodiment of the present invention, a portion of the connecting member is perpendicular to the split portion.
Furthermore, in accordance with another preferred embodiment of the present invention, the support frame is provided with metallic members coupled to the stent and rigid members are positioned on two opposite sides of the metallic member and held against each other holding portion of the pliant material between them, sutured, the metallic members wrapped with PET.
Furthermore, in accordance with another preferred embodiment of the present invention, the device is further provided with spring in order to reduce wear of the pliant material.
Furthermore, in accordance with another preferred embodiment of the present invention, the spring is provided with a spiral.
Furthermore, in accordance with another preferred embodiment of the present invention, the spring is made from stainless steel.
Furthermore, in accordance with another preferred embodiment of the present invention, the spring is attached to slots provided on the support frames.
Furthermore, in accordance with another preferred embodiment of the present invention, the pliant material is sutured to the support frame forming pockets.
Furthermore, in accordance with another preferred embodiment of the present invention, attachment bars are provided on the stent support at a portion of the stent close to the outlet, onto which the pliant material is coupled, and wherein the pliant material is attached circumferentially to the inlet, leaving slack pliant material.
Furthermore, in accordance with another preferred embodiment of the present invention, the outlet is tapered with respect to the inlet.
Furthermore, in accordance with another preferred embodiment of the present invention, the support frame at the outlet is wider in diameter than the pliant material forming the outlet.
Furthermore, in accordance with another preferred embodiment of the present invention, the pliant material is reinforced using PET.
Furthermore, in accordance with another preferred embodiment of the present invention, the support frame is a tube having an inner wall, having sinusoidal fold lines, wherein the pliant material is sutured to the inner wall of the tube along suture lines.
Furthermore, in accordance with another preferred embodiment of the present invention, additional piece of PET is added below the suture lines.
Furthermore, in accordance with another preferred embodiment of the present invention, the device is incorporated with an angioplasty balloon.
Finally, in accordance with another preferred embodiment of the present invention, balloon has a central longitudinal axis that runs along a flow path through the device, and a perimeter, the balloon comprising four inflatable portions, one portion located along a central axis and the other three located on the perimeter, the pliant material in the form of leaflets is distributed about the perimeter.